Air heater



C. E. LUCKE Nov. 5, 1 929.

AIR HEATER Filed Dec. 10, 1927 3 Sheets-Sheet 'i J/wa %M 5M INVENTOR ATTORNEY NOV. 5, l 929. c. LUCKE 1,734,588

AIR HEATER Filed Dec. 10, 192

3 Sheets-Sheet 2 [2 2 ga i INVENTOR ,j W MATTORNEYJ c. E. LucKE Nov. 5, 1 92 9.

AIR HEATER 1927 3 Sheets-5heet Filed Dec. 10

%w {M INVENTOR BY 29 I H/M ATTORNEY5 Patented Nov. 5, 1929 UNITED STATES PATENT OFFICE CHARLES E. LUCKE, OF NEW YORK, N. Y., ASSIGNOR TO THE BABGOGK & WILCOX GOIVII PANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY AIR HEATER Application filed December 10, 1927. Serial No. 239,098.

This invention relates to a device for transferring heat from one fluid to another without permitting the fluids to contact direct- 1y with each other or become mixed. It will be understood from the description in connection with the accompanyingdrawings in which Fig. 1 is a vertical sectionthrough an illustrative embodiment of the invention; Fig. 2 of a vertical section on a large scale showing some of the details; Fig. 3 is a section along the line 8-3 of Fig. 1; Fig. 4 is a vertical section through a modification; Fig. 5 is a section along the line 5-5 of Fig. 4; Fig. 6 is a vertical section through a second modification; Fig. 7 is a section on an enlarged scale showing one of the details; and Fig. 8 is a section along the line 8-8 of Fig. 6.

The invention is especially useful in air heaters in which air is heated by waste products of combustion for furnace combustion purposes, where the differences in pressures are slight and liquid seals can be easily maintained.

In the drawings reference character 1 indicates the casing of the heat exchanger that is provided with an upper tube sheet 2 and a lower tube sheet 3. Vertically disposed tubes 4 extend between the sheets and the upper end of each tube is firmly fixed preferably by expanding into the upper tube sheet 2.

Short sections 8 of tubes are expanded through the lower tube sheet 3 and the outside diameters thereof are of such size that they fit into the insides of the tubes 4 and the space between is sealed by a liquid, and therefore free to expand without leakage. A fluid inlet 9 is provided at the bottom and an outlet 10 at the top for the fluid that passes through the tubes and a fluid inlet 11 is provided through one side of the casing 1 at the top and an outlet 12 is provided through the casing at the bottom for a fluid that passes along the outside of the tubes.

The upper ends of the tubes, instead of being expanded into the upper tube sheet may also be arranged with a liquid seal as in Fig. 2 where tube 4 extends through a sleeve 5 that fits closely in holes in the upper sheet 2. The sleeves 5 are slightly larger than the tubes 4 so that the tubes can move longitudinally in the sleeves due to expansion and contraction or for easy removal upward. Each one of the tubes 4 is provided with a flange 6 that extends downwardly along the outside of the sleeves 5 into a liquid 7 that is maintained on the tube sheet 2. The upper ends of the sleeves 5 extend above the upper surface of the tube sheet 2 to prevent the liquid from entering the sleeves 5 and the flanges 6 terminate between the sheet 2 and the upper ends of the sleeves 5 so that a liquid seal is thereby provided between the fluid on opposite sides of the tube sheet.

In the modification shown in Figs. 4 and 5 the tubes 4 are expanded into tube sheets 2 at the top and 3 at the bottom that are provided alon their edges with downward- 1y extending fianges 14 and 15 that dip into liquid to form liquid seals in the troughs 16 tubes 4 and the lower edge of which extends below the tube sheet 2". The tube sheet 2" and the plate 20 form a receptacle for a liquid. A valved liquid supply pipe 21 leads to the receptacle and an overflow pipe 22 through the plate 20 is located slightly below the level of the upper ends of the tubes. A trough 23 is provided along the inside of the easing into which trough the lower edge of the plate 20 extends and the overflow pipe 22 admits liquid into the trough'23 which provides the seal. An overflow pipe 24 leads through the wall of the casing 1 from the trough 23.

The portion of the tubes 4 that extend above the tube plate 2 are provided with tangential openings 25 as indicated in Fig. 7 so that some of the liquid may enter the inside of these tubes to form films and wash the same as well as collect dust that may be through the tubes.

In the modification shown in Fig. 6 the lower ends of the tubes are made as described in connection with Fig. 1. A valved inlet pipe 27 is provided for the lower portion of the casing and an outlet pipe 28 with an upper bend is provided so that the liquid level is kept in the casing above the lower ends of the tubes 4 and below the upper ends of the tube section 8. This same feature may, of course, be provided in the embodiment shown in Fig. 1.

It will be obvious that the tube can expand and contract freely without the danger of leaks developing so as to mix the heating and heated fluids and may be. lifted out of position for inspection or cleaning. In the embodiment shown in Figs. 1 and 6 the tubes can expand and contract not only with respect to the tube sheets but also with respect to each other and the same is true to a certain extent in the modification shown in Fig. 4. The tubes 4 can be lifted out for repair simply by lifting the upper tube sheets as the lower ends of the tubes 4 will slide ofl of the sections 8 in Fig. 1 and Fig. 6, the lower tube sheet 3 can be easily lifted out of the trough 17 in Fig. 4.

I claim:

1. In a device for transferring heat from one gas to another, tubes, tube sheets at opposite ends of said tubes with open spaces between said gases, and liquid seals in said spaces.

2. In a devicefor transferring heat from one gas to another, tubes, tube sheets at opposite ends of said tubes, means to permit said tubes to expand and contract, and 'a liquid seal between said gases.

3. In a device for transferring heat from one gas to another, tubes, tube sheets at opposite ends of said tubes, and a seal between said gases1 comprising a flange extending into li ui 4. In a device for transferring heat from one gas to another, tubes, a casing, and means to permit relative movement between said tubes and casing, said means comprising flanges extending into liquid.

5. In a device for transferring heat from one gas to another, tubes, a casing and means to permit relative movement between said tubes and casing, said means comprising depending fianges connected to said tubes and ,extending into liquid.

6. In an air heater, tube sheets, telescoping tubes connected to said tube sheets, and a liquid seal for said tubes.

7. In an air heater, tube sheets and telescoping tubes connected to said tube sheets, and a liquid seal between said tubes and one of said tube sheets.

8. In an air heater, tube sheets and tele= scoping tubes connected to said tube sheets,

masses said tubes extending beyond one of said tube sheets and .a liquid seal between said tubes and said tube sheet.

9. In a tubular fluid heater, means to pass a gas through the tubes in one direction and a different gas along the outside of the tubes in the other direction and a liquid seal between the passages for the different gases.

10. In a fluid heater, an upper and a lower tube sheet, tubes between said sheets, and a liquid seal at said upper tube sheet.

11. In an air heater, tube sheets, telescoping tubes connected to said tube sheets, and a seal for said tubes.

12. In an air heater, tube sheets, telescoping tubes connected to said tube sheets, and a yielding closure for the telescoping joints.

13. In an air heater, a casing, tube sheets, tubes connected to one of said tube sheets, and a slidable connection between said tube sheet and easing with a yielding closure for said connection.

14:. In a device for transferring heat from one gas to another, a bank of tubes through which one gas flows and over which another gas flows, and means including a liquid seal located at one end of said bank for preventing admixture of said gases.

15. In a device for transferring heat from one gas to another, tubes, a casing, means to permit relative movement between said tubes and casing, said means including a liquid seal for preventing admixture of said gases.

GI-IARLES E. LUCKE. 

